This invention relates in general to control devices and in particular to a new and useful device for breaking down a mixture.
Devices for breaking down mixtures by means of an adsorbent permit the production of an enriched product, e.g. oxygen for technical processes or for the ventilation of many from the surrounding atmosphere, and make it independent of the storage and re-supply organization for this gas.
A known control for a device for breaking down a mixture, particularly for an oxygen separator, permits the continuous delivery of an oxygen-rich gas as a product upon the supply of compressed air. The device is switched periodically by a pneumatic control between two operating stages in which the compressed air is fed to one of the tanks contained in the device with adsorbent, and the other tank is at the same time regenerated and vice versa. Switching criteria are the attainment of a certain pressure in the tank supplied with compressed air, which indicates that it is exhausted. The release of the control for ending the respective operating state is effected over a push button when the given limit pressure in the mixture supply has been attained. Then a pressure equilibrium is established between the two tanks. After this is achieved, the control is released at the start of the following operating state by a pressure equalizing switch which is connected at the same time to both tanks.
Specifically the mixture to be broken down is supplied from the compressed air source over a mixture supply. The mixture supply can be connected by an inlet valve over the control with the inlet of the first tank and of the second tank. The outlet of the tanks can be connected over an outlet valve with the atmosphere. The inlet valve of the first tank and the outlet valve of the second tank are combined for control to a first valve arrangement and connected to the control. Likewise, the inlet valve of the second tank and the outlet valve of the first tank are combined to a valve arrangement and connected to the control. The outlets of the first tank and of the second tank are connected with each other over a choke and over a pressure reducer to the line to the load.
The above-described system does not take into consideration tolerances between the tanks, as they result, i.e. from the filling, and then also by fluctuations in the volume current. Neither the adsorbent pressure alone, nor the adsorption time, as it results from the volume current resulting from the pressure until the adsorbent is exhausted, determine the optimum utilization and the end of the absorption cycle (German OS No. 29 51 626).